/*
 * Copyright (c) 2007 innoSysTec (R) GmbH, Germany. All rights reserved.
 * Original author: Edmund Wagner
 * Creation date: 22.05.2007
 *
 * Source: $HeadURL$
 * Last changed: $LastChangedDate$
 * 
 * 
 * the unrar licence applies to all junrar source and binary distributions 
 * you are not allowed to use this source to re-create the RAR compression algorithm
 *
 * Here some html entities which can be used for escaping javadoc tags:
 * "&":  "&#038;" or "&amp;"
 * "<":  "&#060;" or "&lt;"
 * ">":  "&#062;" or "&gt;"
 * "@":  "&#064;" 
 */
package de.innosystec.unrar.rarfile;

import de.innosystec.unrar.io.Raw;

/**
 * Base class of all rar headers
 * 
 * @author $LastChangedBy$
 * @version $LastChangedRevision$
 */
public class BaseBlock {

	public static final short BaseBlockSize = 7;

	// TODO move somewhere else

	public static final short MHD_VOLUME = 0x0001;
	public static final short MHD_COMMENT = 0x0002;
	public static final short MHD_LOCK = 0x0004;
	public static final short MHD_SOLID = 0x0008;
	public static final short MHD_PACK_COMMENT = 0x0010;
	public static final short MHD_NEWNUMBERING = 0x0010;
	public static final short MHD_AV = 0x0020;
	public static final short MHD_PROTECT = 0x0040;
	public static final short MHD_PASSWORD = 0x0080;
	public static final short MHD_FIRSTVOLUME = 0x0100;
	public static final short MHD_ENCRYPTVER = 0x0200;

	public static final short LHD_SPLIT_BEFORE = 0x0001;
	public static final short LHD_SPLIT_AFTER = 0x0002;
	public static final short LHD_PASSWORD = 0x0004;
	public static final short LHD_COMMENT = 0x0008;
	public static final short LHD_SOLID = 0x0010;

	public static final short LHD_WINDOWMASK = 0x00e0;
	public static final short LHD_WINDOW64 = 0x0000;
	public static final short LHD_WINDOW128 = 0x0020;
	public static final short LHD_WINDOW256 = 0x0040;
	public static final short LHD_WINDOW512 = 0x0060;
	public static final short LHD_WINDOW1024 = 0x0080;
	public static final short LHD_WINDOW2048 = 0x00a0;
	public static final short LHD_WINDOW4096 = 0x00c0;
	public static final short LHD_DIRECTORY = 0x00e0;

	public static final short LHD_LARGE = 0x0100;
	public static final short LHD_UNICODE = 0x0200;
	public static final short LHD_SALT = 0x0400;
	public static final short LHD_VERSION = 0x0800;
	public static final short LHD_EXTTIME = 0x1000;
	public static final short LHD_EXTFLAGS = 0x2000;

	public static final short SKIP_IF_UNKNOWN = 0x4000;
	public static final short LONG_BLOCK = -0x8000;

	public static final short EARC_NEXT_VOLUME = 0x0001;
	public static final short EARC_DATACRC = 0x0002;
	public static final short EARC_REVSPACE = 0x0004;
	public static final short EARC_VOLNUMBER = 0x0008;

	protected long positionInFile;

	protected short headCRC = 0;
	protected byte headerType = 0;
	protected short flags = 0;
	protected short headerSize = 0;

	/**
	 * 
	 */
	public BaseBlock() {

	}

	public BaseBlock(BaseBlock bb) {
		this.flags = bb.getFlags();
		this.headCRC = bb.getHeadCRC();
		this.headerType = bb.getHeaderType();
		this.headerSize = bb.getHeaderSize();
		this.positionInFile = bb.getPositionInFile();
	}

	public BaseBlock(byte[] baseBlockHeader) {

		int pos = 0;
		this.headCRC = Raw.readShortLittleEndian(baseBlockHeader, pos);
		pos += 2;
		this.headerType |= baseBlockHeader[pos] & 0xff;
		pos++;
		this.flags = Raw.readShortLittleEndian(baseBlockHeader, pos);
		pos += 2;
		this.headerSize = Raw.readShortLittleEndian(baseBlockHeader, pos);
	}

	public boolean hasArchiveDataCRC() {
		return (this.flags & EARC_DATACRC) != 0;
	}

	public boolean hasVolumeNumber() {
		return (this.flags & EARC_VOLNUMBER) != 0;
	}

	public boolean hasEncryptVersion() {
		return (flags & MHD_ENCRYPTVER) != 0;
	}

	/**
	 * @return is it a sub block
	 */
	public boolean isSubBlock() {
		if (UnrarHeadertype.SubHeader == headerType) {
			return (true);
		}
		if (UnrarHeadertype.NewSubHeader == headerType && (flags & LHD_SOLID) != 0) {
			return (true);
		}
		return (false);

	}

	public long getPositionInFile() {
		return positionInFile;
	}

	public short getFlags() {
		return flags;
	}

	public short getHeadCRC() {
		return headCRC;
	}

	public short getHeaderSize() {
		return headerSize;
	}

	/**
	 * byte, one of UnrarHeadertype.
	 * 
	 * @return
	 */
	public byte getHeaderType() {
		return headerType;
	}

	public void setPositionInFile(long positionInFile) {
		this.positionInFile = positionInFile;
	}

}
